The present invention relates to a method for joining sheet materials and in particular to a method of packaging an article employing that method.
Known packaging materials include a layer of aluminium foil which has on one side thereof a layer of heat sealable material such as, for example, SURLYN (Registered Trade Mark). In order to form a seal between the two edges of the material, two surface portions of the packaging material which have the heat sealable layer are brought into contact and heat sealed. It has been found that using that packaging material the seal formed by that known method provides adequate strength and is quite satisfactory for the exclusion of air, water and other extraneous materials. However, it does not provide a reliable shield against electro-magnetic fields.